simplify Terminate exception

spalloc_client/scripts/job.py

@@ -241,9 +241,9 @@ def power_job(client, timeout, job_id, power):
                 raise Terminate(7) from exc
         else:
             # In an unknown state, perhaps the job was queued etc.
-            raise Terminate(8, "Error: Cannot power {} job {} in state {}",
-                            "on" if power else "off",
-                            job_id, _state_name(state))
+            raise Terminate(
+                8, (f"Error: Cannot power {'on' if power else 'off'} "
+                    f"job {job_id} in state {_state_name(state)}"))
 
 
 def list_ips(client, timeout, job_id):
@@ -267,7 +267,7 @@ def list_ips(client, timeout, job_id):
     info = client.get_job_machine_info(job_id, timeout=timeout)
     connections = info["connections"]
     if connections is None:
-        raise Terminate(9, "Job {} is queued or does not exist", job_id)
+        raise Terminate(9, f"Job {job_id} is queued or does not exist")
     print("x,y,hostname")
     for ((x, y), hostname) in sorted(connections):
         print("{},{},{}".format(x, y, hostname))
@@ -308,11 +308,11 @@ def get_job_id(self, client, args):
         jobs = client.list_jobs(timeout=args.timeout)
         job_ids = [job["job_id"] for job in jobs if job["owner"] == args.owner]
         if not job_ids:
-            raise Terminate(3, "Owner {} has no live jobs", args.owner)
+            raise Terminate(3, f"Owner {args.owner} has no live jobs")
         elif len(job_ids) > 1:
-            raise Terminate(3, "Ambiguous: {} has {} live jobs: {}",
-                            args.owner, len(job_ids),
-                            ", ".join(map(str, job_ids)))
+            msg = (f"Ambiguous: {args.owner} has {len(job_ids)} live jobs: "
+                   f"{', '.join(map(str, job_ids))}")
+            raise Terminate(3, msg)
         return job_ids[0]
 
     def get_parser(self, cfg):

spalloc_client/scripts/machine.py

@@ -98,7 +98,7 @@ def _get_machine(machines, machine_name):
         if machine["name"] == machine_name:
             return machine
     # No matching machine
-    raise Terminate(6, "No machine '{}' was found", machine_name)
+    raise Terminate(6, f"No machine '{machine_name}' was found")
 
 
 def show_machine(t, machines, jobs, machine_name, compact=False):

spalloc_client/scripts/support.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import sys
+from typing import Optional
 from spalloc_client import (
     config, ProtocolClient, ProtocolError, ProtocolTimeoutError,
     SpallocServerException)
@@ -24,17 +25,10 @@
 
 
 class Terminate(Exception):
-    def __init__(self, code, *args):
+    def __init__(self, code: int, message: Optional[str] = None):
         super().__init__()
         self._code = code
-        args = list(args)
-        message = args.pop(0) if args else None
-        if message is None:
-            self._msg = None
-        elif args:
-            self._msg = message.format(*args)
-        else:
-            self._msg = message
+        self._msg = message
 
     def exit(self):
         if self._msg is not None:
@@ -45,8 +39,8 @@ def exit(self):
 def version_verify(client, timeout):
     version = tuple(map(int, client.version(timeout=timeout).split(".")))
     if not (VERSION_RANGE_START <= version < VERSION_RANGE_STOP):
-        raise Terminate(2, "Incompatible server version ({})",
-                        ".".join(map(str, version)))
+        raise Terminate(
+            2, f"Incompatible server version ({'.'.join(map(str, version))})")
 
 
 class Script(object):